For the machine you listed pretty much anything will do that's decent quality. You will probably be running at 150 watts in use or less.
Things like http://www.newegg.com/Product/Product.aspx?Item=N82E16817151077
would do just fine
The question is the future proofing. Are you going to be using the case/PSU combo to build a similar low power machine in the future or is this a build that you will be using for a year or three and then want to build up to a much more powerful gaming rig at that time? If that's the case then 3hunna's suggestion of something like the XFX 550 or a similar quality unit around 500-600 watts would be a better choice.
I'm going to probably reuse the case and psu for future purposes, a simple yet more powerful gaming rig - probably a full ATX and a better processor of course; Will the 500-700 range still be effective by then? Let's assume I'll also get a better video card aaand no need for those flashy lights things and expensive fans.
A 550 is more than enough for any normal single GPU machine. You might be able to design one that needs something more, but if you knew what to pick for that you'd already know what more you need for your power supply too. Unless you are going for a 980ti or the equivalent then, and tons of drives and fans and lights and pumps... then yeah, a 550 will do just fine.